Implementation of building envelop energy efficiency measures in existing detached houses

1. Implementation of building envelop energy efficiency measures in existing detached houses Leif Gustavsson & Krushna Mahapatra Dept. of Engineering and Sustainable Development Mid Sweden University Leif.gustavsson@miun.se; Krushna.mahapatra@miun.se May 06, 2009 Katrineholm

2. Introduction • Residential and service sector uses 1/3rd of total final energy use in Sweden • Considerable scope for improving energy efficiency in the existing buildings • decrease energy use by 30 TWh of heat and 15 TWh of electricity (CEC, 2005) • Successful implementation of changes depends on attitudes and perceptions of the relevant actors • Actors involved vary over the building stock as houses vary in age, size, management and ownership

3. Research questions • To study homeowners’ perception of building envelop energy efficiency measures in detached houses • To study the role of energy utilities and energy advisors in influencing homeowners’ decision to adopt energy efficiency measures • To study perceptions and attitudes of the manufacturers, retailers, installers and building companies’ towards energy efficiency • To analyze the effects of policy measures related to energy and climate change in the context of energy efficiency • To give an overview of the drivers to perform energy efficiency improvements, depending on the ownership and management situation

4. Source: Energy in Sweden, 2008

5. Annual primary energy use with installation of heating systems and energy efficiency measures Electricity supply systems: coal-based steam turbines (CST), natural gas-based combined cycle (NGCC), and biomass with integrated combined cycle technology (BIG/CC) Source: Joelsson, A. (2008). Primary Energy Efficiency and CO2 Mitigation in Residential Buildings, PhD Thesis 58, Mid Sweden University, Sweden,.

6. Influence of government policy instruments, e.g. subsidies Need for a new installation Age, physical condition, aesthetics,and energy performance of existing installation, awareness about better alternative, perceived higher utility bill, demographic factors Stage 1 Mass media, interpersonalcommunications, change agents Collection of Information Stage 2 Perceived advantages - Economic - Ease of installation - Environmental Selection of an installation Stage 3 Stages in homeowners’ adoption of a building envelop energy efficiency measures Adapted from Hawkins et al., 2007; Mahapatra and Gustavsson, 2008

7. Survey of homeowners • 3000 homeowners selected through stratified random sampling • Survey through Statistics Sweden during May-July 2008 • 36% response rate after two reminders • No non-response bias • Geographical location, age of house and respondents’ income • Higher aged (>55 yrs) people are over-represented by about 5%

8. Actions respondents may take to improve efficiency of household energy use (1)

9. Personal interviews March-June 2008 N=1007, statified random sampling Installed equipments that generate renewable energy Switched to an energy supplier or tariff supplying a greater share of energy from renewables Actions respondents may...(2) Source: Europeans’ attitudes towards climate change, Eurobarometer 300, 2008

10. Homeowners' plan to install an energy efficiency measure

11. Age of existing installation

12. Age of installation vs. respondents’ plan to change window or attic insulation

13. Respondents’ perception of various attributes of existing installations % of respondents Wall insulation Window Attic insulation Wall insulation Window Window Facade Attic insulation Aesthetics Physical condition Thermal performance

14. Respondents level of satisfaction with thermal performance of existing installation vs. their plan to change window or attic insulation

15. Respondents perception of energy cost burden vs. their plan to change window or attic insulation

16. Respondents household income vs. their plan to change window or attic insulation

17. Respondents’ level of education vs. their plan to change window or attic insulation (%)

18. Respondents’ age vs. their plan to change window or attic insulation (%)

19. Homeowners’ perception of importance of sources of information on energy efficiency measures

20. Respondents’ awareness of energy advice service • Are you aware about existence of energy adviser in your locality? (N=1061) • Yes = 50% • No = 7% • Do not know = 43%

21. Actual consultation with external actors for household energy reduction N = Number of respondents

22. Perceived quality of external actors' suggestion N = Number of respondents who contacted the respective source

23. Respondents’ implementation of energy advisers’ suggestions • 57% of those consulted an energy adviser implemented the suggestions (≈8% of total respondents) • 43% did not implement the suggestions mainly because • suggestions were not specific (21%) • already implemented (24%) • expensive to be implemented (33%) • other reasons (22%)

24. Important factors in homeowners’ choice of energy efficiency measures (decreasing order of importance) A higher mean indicates higher importance

25. Awareness about subsidies • About 36% of respondents knew about government support for adoption of energy efficiency measures of which • About 1/3rd knew about investment subsidies for windows of which • 53% (≈ 6% of total respondents) considered the subsidy important in their adoption decision

26. Homeowners’ perception of annual energy cost

27. Homeowners’ perception of GHG emission reduction

28. Perceived advantages of energy efficiency measures

29. Energy efficiency measure that respondents would recommend to peers and friends

30. % of respondents reporting the year of installation of existing windows and attic insulation Age of installation Conclusion: Attic insulation is preferred but more windows are installed

31. Greater observability of windows

32. Main findings • 70 – 90% do not plan to install a building envelope energy efficiency measure • Economic factors guide adoption decision • Environmental factors are given low priority • Large proportion of respondents do not know about various attributes of building envelope energy efficiency measure • Attic insulation has greater perceived advantages, but windows are more adopted • Investment subsidy, observability • Interpersonal source, construction companies, installers, and energy advisors are important sources of information • Large percentage of homeowners are unaware about the energy advisers in their area or dissatisfied with their suggestions

33. Suggestions that may increase adoption of building envelop energy efficiency measures • Economic instruments useful • Improve awareness among homeowners about economic instruments and economic efficiency of adopting building envelope components • Facilitate a more effective interaction between important external actors and homeowners • More publicity and competence development of energy advisers

34. Thank you for your attention!